Germination of Forest Trees 



4i 



words, only 2 species had a higher germination per cent, in the 

 open light than in the shade. 



On page 40 are given the germination curves of the two New 

 Mexico species, Pinus ponderosa and Pseudotsuga taxifolia. 

 While these do not show a higher germination per cent, in the 

 dense shade than in the open light they show the characteristic 

 rapid rise of the shade curves and the fact that germination begins 

 earlier in the shade than in the light. 



TABLE III 



The Effect of Light on Germination 



Pacific Coast Species 



Species 



Open Light 



Medium Shade 



he rt 



be « 

 OJQ 



Dense Shade 



JiC, 



Pinus ponderosa (Calif.) .... 



Pinus jeffreyi 



Pinus lambertiana 



Pinus coulteri 



Abies magnifica 



Libocedrus decurrens 



Sequoia washingtoniana 



Tsuga heterophylla 



Picea sitkensis 



Larix occidentalis 



Pseudotsuga taxifolia (Wash.) . 



61.0 



22.0 



2.5 



15-5 



18.0 



6.0 



7.0 



0-5 



22.5 

 O 



6.0 



62.0 

 14.0 



4.0 

 18.0 

 30.0 



4.0 



5-5 







34-0 



0-5 

 13.0 



20 

 70 

 52 

 36 

 16 

 14 

 



14 

 70 

 14 



62 



54 

 24 

 62 

 54 

 52 

 14 







36 



I 



62 



42.0 

 17.0 



7.0 

 23.0 



10. 



9.0 



8.5 







38.0 

 0.5 



22.0 



Out of the 11 Pacific coast species listed in Table III, 7 germi- 

 nated in the dense shade before they did in the open light culture, 

 2 germinated simultaneously in the light and shade and 2 species 

 did not germinate sufficiently to warrant conclusions. Pinus pon- 

 derosa (Calif.) germinated 20 days earlier in the dense shade 

 than in the light, Pinus jeffreyi 11 days, Abies magnifica 8 days, 

 Libocedrus decurrens 13 days, Sequoia washingtoniana 2 days, 

 Picea sitkensis 8 days and Pseudotsuga taxifolia (Wash.) 8 days. 



Six species showed longer germination periods in the shade, 

 three in the open light, and two species did not germinate sufficiently 

 to be considered. Only one species, Pinus jeffreyi, showed a 

 higher germination per cent, in the open light, two species showed 



